Sayo (小夜, さよ, "Born at Night") is a village girl who became very attached to Kikyō and longed to have Kikyō as a sister shortly after her resurrection. Because she reminded Kikyō of her younger sister Kaede, Kikyō treated her affectionately, along with many of the other village children.

However, when Seikai, a traveling monk, attempted to exorcise Kikyō, believing she is demonic or possessed, Kikyō kills him in retaliation. The act is witnessed by Sayo, who had unexpectedly been following Kikyō. Realizing that she has frightened Sayo with her true nature and by killing Seikai, Kikyō left the village and resolved never to remain in one place again. Though Sayo asked for Kikyō to wait, Kikyō left anyways, bidding farewell to Sayo and asked for the girl to forgive her.